As one seat frame of a vehicle seat, there is a seat frame in which a lower portion of a back frame is connected to a rear portion of a cushion frame having a rectangular frame shape in a top view. Here, the cushion frame is configured in such a manner that a pair of side frames extends in a front and rear direction at an interval in a seat width direction, front end portions of the pair of side frames are connected in a bridging manner by a front frame, rear end portions of the pair of side frames are connected in a bridging manner by a rear frame, and a panel member is disposed between the front frame and the rear frame. In such a type of cushion frame disclosed in Japanese Patent No. 5359880, a panel member formed of an elastically deformable metal plate is disposed between a front pipe serving as the front frame and a rear frame serving as the rear frame. A cushion pad serving as a cushion body is placed on the panel member. Further, a lower portion of a back frame is connected to a rear portion of each of the pair of side frames via a recliner.
In the seat frame described above, the panel member of the cushion frame has a function of supporting the cushion pad, but does not have a function of enhancing the strength and rigidity of the pair of side frames, the front frame, and the rear frame. Therefore, it has been demanded to provide a seat frame with a cushion frame, which can be reduced in weight as a whole by imparting a function of reinforcing the pair of side frames, the front frame, and the rear frame to the panel member.